<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<style>
.a1{
   width: 100px;
   height: 100px;
   background-color: gold;
   border-radius: 10px; 
   margin: 30px auto;
   position: relative;
}
.a1>div{
    width: 28px;
    height: 28px;
    background-color: red;
    border-radius: 50%;
    line-height: 28px;
    text-align: center;
    position: absolute;
    color: white;
    left: 86px;
    top: -14px;
}
</style>
<body>
    <div class="a1">
        <div>5</div>
    </div>
</body>
</html>